The Boston Red Sox haven't failed in their ability to develop young pitchers in the last couple of years. First came Brayan Bello, now it's Payton Tolle, Brandon Clarke, and Hayden Mullins.
Hayden Mullins is 24 years old, drafted out of Auburn University in the 12th round of the 2022 draft. Unfortunately, he had to undergo Tommy John Surgery in 2022 and couldn't get started right away. But when he came back at the end of 2023, he got right back into where he started from.
Red Sox Prospect Hayden Mullins Is Long Overdue for a Call-Up
2024 was much better than his small sample size in 2023, and he broke out in High-A Greenville. He posted a 3.94 ERA with 118 strikeouts in 89 full innings and 22 games. However, he's turned into a different form in 2025, with a 1.97 ERA, already having just over 100 strikeouts in both High-A Greenville and AA Portland. He's soaring through the system and is currently sitting at #18 on the Red Sox prospect list.
I was privileged to have a sit-down with him on Saturday, and he was not only a splendid talent but a great and personable human being. I had asked about one thing that the Red Sox were working on with him, and he said the team's working on his velocity. "The result, hopefully, is adding velocity to my fastball", Mullins said before the game, "all that comes from the weight room, training staff, nutrition, just getting bigger, stronger, faster."
He proved himself even more worthy of a call-up yesterday with his outstanding performance. Six full innings, gave up only one earned run on two hits, striking out seven batters, on just 77 pitches. His ERA in AA is at 2.20, with a 1.06 WHIP, with 74 strikeouts in 65.1 innings.
Mullins is an outstanding talent, and one that is commonly overlooked by other names in the system. Expect him to climb that ladder within the next few weeks.